Present address: 45 rue des Saints Pères, 75006 Paris, France.
Axonal GABAA receptors
Version of Record online: 8 AUG 2008
© The Authors (2008). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd
European Journal of Neuroscience
Volume 28, Issue 5, pages 841–848, September 2008
How to Cite
Trigo, F. F., Marty, A. and Stell, B. M. (2008), Axonal GABAA receptors. European Journal of Neuroscience, 28: 841–848. doi: 10.1111/j.1460-9568.2008.06404.x
- Issue online: 26 AUG 2008
- Version of Record online: 8 AUG 2008
- Received 7 May 2008, revised 27 June 2008, accepted 8 July 2008
- synaptic physiology
Type A GABA receptors (GABAARs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABAARs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABAARs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABAAR modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABAARs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABAARs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABAARs persist into adulthood. Altogether, axonal GABAARs appear as potent neuronal modulators of the mammalian CNS.